A supply unit of the kind described above is disclosed, for example, in U.S. Pat. No. 3,615,250. This publication discloses an oxygen generator as well as several oxygen masks which are accommodated in a housing disposed in the roof structure of the passenger compartment of an aircraft. When required, the housing can be opened by means of a flap with the oxygen generator being ignited after the oxygen masks are pulled out of the housing. The oxygen generator then delivers the needed oxygen for breathing for a predetermined time. For the known oxygen supply unit, the essential individual parts such as the oxygen generator and the oxygen masks are individually accommodated on the base wall of the housing so that the latter must have the required mechanical strength in order to withstand the loading which occurs during operation of the aircraft. Complex bracing and thickened material are provided so that the occurring forces can be taken up.
In jumbo aircraft especially, every possible savings in weight leads to a reduction of the operational cost so that the above-mentioned supporting structure should be avoided, especially because every row of seats must be assigned such an oxygen supply unit.
Larger oxygen generators are necessary especially for providing a longer needed oxygen supply so that their use makes it necessary to provide for further reinforcement of the housing accommodating the generators.